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1. Field of Invention
This invention pertains to the recording and/or reproduction of information on magnetic tape media.
2. Related Art and Other Considerations
In magnetic recording on tape using a magnetic tape drive, relative motion between a head unit (typically with both a write element and a read element) and the tape causes a plurality of tracks of information to be transduced with respect to the tape. One example of magnetic tape recording is streaming recording, such as serpentine recording. In serpentine recording, the relative motion between the head unit and the tape occurs primarily along the longitudinal axis of the tape to follow or form a track, with the vertical position between the tape and the head unit being adjusted for a change of tracks. The head unit thus travels longitudinally back and forth along the tape, changing tracks typically at longitudinal ends of the tape.
The magnetic tape is typically housed in a cartridge which is loaded into the tape drive. The tape is extracted by the drive from the cartridge into a tape path that travels proximate the head unit.
Some magnetic tape is preformatted so that frames or blocks of information are correlated with specific physical locations on tape. Tape preformatted in this manner is called "hard sectored" tape.
Typically in magnetic tape recording, when a block or frame of information is recorded on the tape, the block or frame is read back for verification purposes, either essentially immediately during the recording process by a read head which follows the write head along the track, or subsequently. In such a verification read-back, for streaming data if it is determined that the frame or block cannot be read or contains an error, the contents of such frame or block are re-recorded on the tape. Such re-recording is required for data integrity, but does hamper recording and reproduction rates.
Magnetic tape has historically been useful as a media for storing computer information, e.g., for backing up a computer or for storing computer data which is too voluminous to remain resident at the computer. In other applications, magnetic tape has also been useful for storing audio information, video information, or audio/visual information. Verification of recorded data is typically not provided in such audio/visual applications in view of the requirements for near real-time recording and reproduction rates.
More recently, a use for magnetic tape has been proposed for set-top boxes. A set-top box provides a direct satellite connection to a television, whereby a viewer can have a program downloaded by satellite connection in real time for viewing on the television. It has been recently proposed that magnetic tape be utilized to record the satellite-downloaded information received by the set-top box so that a program can be preserved for viewing, e.g., at a later time.